海洋沉积物微生物介导有机碳转化研究进展

Research progress on microbiome and organic carbon transformation in marine sediment

摘要:

海洋沉积物是地球上最大的有机碳库，其中生存的微生物总量大、分布范围广、类群多样、代谢方式复杂，并共同构成海洋沉积物微生物组。海洋沉积物微生物组介导的有机碳降解与矿化过程不但能为沉积物中的生命活动提供物质和能量，也能参与调控碳循环过程，并在长时间尺度上对地球气候系统产生重大影响。沉积物中的有机碳在复杂多样的微生物代谢活动下被逐步降解，其最终的矿化过程与不同的电子受体消耗相偶合，并形成对应的地球化学分区。研究海洋沉积物微生物及其介导的有机碳转化过程对我们深入认识沉积物中的元素循环过程，并进一步评估其对整个地球系统的影响具有重要科学意义。本文对海洋沉积物微生物组的体量、包含的微生物多样性、代谢活性以及在不同地球化学分区中主要的微生物类群和代谢机制进行综述，最后基于研究现状展望了海洋沉积物微生物组的未来研究方向。

Abstract:

Marine sediment is the largest organic carbon reservoir on Earth, and the microorganisms thereof constitute the marine sediment microbiome which are in large quantity, widely distributed, with diversified lineages and versatile metabolic capacities. The organic carbon degradation and mineralization processes mediated by the marine sedimentary microbes not only provide material and energy for life in the sediments, but also participate in carbon cycling processes and have a significant impact on the Earth՚s climate system for long time scales. Organic carbon in sediments is gradually degraded by complex microbial metabolic activities, and its final mineralization process sequentially couples with the depletion of different electron acceptors which forms the corresponding geochemical zones in marine sediment. The study of marine sedimentary microbiome and the associated organic carbon transformation processes is important for our in-depth understanding of elemental cycling processes in sediments and further assessment of their impact on the Earth system. This review provides an overview of the quantity of the marine sediment microbiome, the diversity of microorganisms, their metabolic capacities as well as the major microbial taxa and metabolic mechanisms that forms geochemical zones. Finally, based on the current research status, the future research directions of marine sedimentary microbiome are prospected.